The present invention relates to apparatus for and method of producing semiconductor devices, and more particularly, to a method and apparatus for producing semiconductor devices which is provided with a mold and a lead frame suitable for improving the production efficiency and product quality.
As disclosed in Japanese Patent Pre-examination Publication No. 61-292330 and Japanese Utility Model Pre-examination Publication No. 62-157143, a conventional apparatus includes a plurality of pots which communicate with each other via auxiliary runners are provided in a mold, and one product cavity is connected to a tip of each of a pair or two pairs of main runners which are connected to pots. In addition, as disclosed in Japanese Patent Pre-examination Publication No. 62-122136, another conventional apparatus is so constructed that a plurality of product cavities are connected in series to the respective tips of the runners.
In the prior art disclosed in Japanese Patent Pre-examination Publication No. 61-29230 and Japanese Utility Model Pre-examination Publication No. 62-157143, even if the amounts of tablets charged into pots through flow paths between pots vary, the apparatus has the effect of being capable of making uniform the internal pressure of the flow passages between the pots. However, only one cavity is provided at the tip of each runner, and an excessive amount of resin is required for filling the flow passages, so that there have been limitations to improving the yield.
In the other prior art referred to above, the apparatus is so constructed that a plurality of cavities are connected in series to each runner, respectively independently, led from a plurality of pots. However, since the weights of tablets charged into each pot usually vary, there have been limitations to uniformalizing the internal pressures in the flow passages between the pots.
In other words, in the prior art, no consideration has been paid to making effective use of the resin and uniformalizing the internal pressures in the flow passages between the pots in the mold.